A clinical approach to obstructive sleep apnea as a risk factor for cardiovascular disease

Abstract

Obstructive sleep apnea (OSA) is associated with cardiovascular risk factors, cardiovascular diseases, and increased mortality. Epidemiological studies have established these associations, and there are now numerous experimental and clinical studies which have provided information on the possible underlying mechanisms. Mechanistic proof-of-concept studies with surrogate endpoints have been performed to demonstrate that treatment of OSA by continuous positive airway pressure (CPAP) has the potential to reverse or at least to attenuate not only OSA but also the adverse cardiovascular effects associated with OSA. However, no randomized studies have been performed to demonstrate that treatment of OSA by CPAP improves clinical outcomes in patients with cardiovascular risk factors and/or established cardiovascular disease and concomitant OSA. In the present review, we summarize the current knowledge on the role of OSA as a potential cardiovascular risk factor, the impact of OSA on cardiac function, the role of OSA as a modifier of the course of cardiovascular diseases such as coronary artery disease, atrial fibrillation, and heart failure, and the insights from studies evaluating the impact of CPAP therapy on the cardiovascular features associated with OSA.

Keywords: atrial fibrillation; cardiovascular; heart failure; hypertension; obstructive sleep apnea; risk.

Figure 1

Schematic representation of the OSA-related effects on cardiac structure and function. Note: Red, effects on the left heart; blue, effects on the pulmonary circulation and right heart. Abbreviations: LA, left atrium/atrial; LV, left ventricle/ventricular; OSA, obstructive sleep apnea; RA, right atrium/atrial; RV, right ventricle/ventricular.

Figure 2

Illustration of the possible interplay between classical cardiovascular risk factors and cardiac diseases, and the role of OSA. Notes: The black arrows indicate the effects by OSA on risk factors/cardiac diseases. The gray arrows indicate the coexisting effects between risk factors/cardiac diseases, which together with the OSA-related effects may eventually lead to heart failure. Abbreviations: AF, atrial fibrillation; CAD, coronary artery disease; HFpEF, heart failure with preserved ejection fraction; HFrEF, heart failure with reduced ejection fraction; OSA, obstructive sleep apnea.